import java.util.*;

public class Main {

    //
    public static void main1(String[] args) {
        Scanner in = new Scanner(System.in);
        while(in.hasNext()){
            int n = in.nextInt();

            int ret = 1;
            while(ret - 1 <= n) { ret *= 2;}
            System.out.println(ret / 2 - 1);
        }
    }

    //
    public static void main2(String[] args) {
        Scanner in = new Scanner(System.in);
        char[] a = in.next().toCharArray();
        char[] b = in.next().toCharArray();
        int n = a.length, m = b.length;

        int[][] dp = new int[n + 1][m + 1];
        for(int j = 1; j <= m; j++) { dp[0][j] = j;}
        for(int i = 1; i <= n; i++) { dp[i][0] = i;}

        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= m; j++){
                if(a[i - 1] == b[j - 1]){
                    dp[i][j] = dp[i - 1][j - 1];
                }else{
                    dp[i][j] = Math.min(dp[i - 1][j - 1], Math.min(dp[i - 1][j], dp[i][j - 1])) + 1;
                }
            }
        }
        System.out.println(dp[n][m]);
    }
}
